The invention relates to a coupling device for a multi-phase converter and a multi-phase converter.
A power converter, which can also be referred to as a direct current converter or DC-DC converter, is designed to convert a DC voltage at an input into a DC voltage having another voltage level. Such a power converter can also be designed as a multi-phase converter comprising coupled inductors. Coupled multi-phase converters comprise a plurality of phases, wherein each phase is passed through a current carrying conductor, said phases being coupled to one another by means of magnetic coupling means. A current ripple through the magnetic coupling, which is generated by each phase, can however impair the operation of the multi-phase converter. That is why sections of the individual conductors are to be suitably arranged relative to one another in order, for example, to prevent disadvantages from occurring in an electromagnetic compatibility.
The WIPO patent publication WO 2012/028558 A1 describes a multi-phase converter in which a mutual interference of the phases is minimized and a large portion of the magnetic flux is compensated by means of the magnetically oppositely-directed coupling of one phase of at least six phases comprising at least three further phases. The phases to be coupled are thereby selected such that an optimal compensation can be achieved. This results from an oppositely-directed current profile of the phases. The goal here is for the phases to be magnetically coupled in such a way that the resulting magnetic field is minimized due to the coupled phases. In so doing, a ferrite core is used for coupling the magnetic fluxes in order to profit from the high permeability of the material. In the case of the coupling proposed here, the phases can be actuated successively and independently of one another.